Machine for manufacturing air cavity building blocks



May 14, 1963 J. M. WOLFF 3,089,214

MACHINE FOR MANUFACTURING AIR CAVITY BUILDING BLOCKS Filed Oct. 6, 1959 '7 Sheets-Sheet 1 I TKi: v n i m T 1 D. 3: (C4 (.2 042;

INVENTOR. 4 Mom J. M. WOLFF May 14, 1963 7 Sheets-Sheet 2 Filed Oct. 6, 1959 M i.. J 21 w, T :2 F I Z w 1 m n M f t w m, H m n IN VEN TOR. do: flweca h our lls J. Mv WOLFF May 14, 1963 MACHINE FOR MANUFACTURING AIR CAVITY BUILDING BLOCKS Filed Oct. 6, 1959 7 Sheets-Sheet 3 INVENTOR.

J05 NW4 607- 4; A; @zt

MACHINE FOR MANUFACTURING AIR CAVITY BUILDING BLOCKS Filed Oct. 6, 1959 J. M. WOLFF May 14, 1963 '7 Sheets-Sheet 4 INVENTOR. b: fiAfQZ h OLFF BY 44., 14 A 1 A H Nu? May 14, 1963 J. M WOLFF 3,089,214

MACHINE FOR MANUFACTURING AIR CAVITY BUILDING BLOCKS Filed Oct. 6, 1959 '7 Sheets-Sheet 5 AWOP/YHS BY 44L, [.4 I;

0,||| lul- R. F 0@ A. w W o@ m u w a or 1 x Q. @r M mm. @m m d X \@v 8 8. mv m\ mm m. am 8 mm 9 m 5. awn-0w F 8 i or m .WIH maw On J9 a: ma \0@ w E Q do Hm mm 2 h 30 I w 8. If 7/ to M1. OOH E 1 m $2 5. m9 am me am. 3. a: 8. 9 09 mm v0. E. 2 F A NJ H@ Or 3 Hr N. w

MACHINE FOR MANUFACTURING AIR CAVITY BUILDING BLOCKS Filed Oct. 6, 1959 J. M. WOLFF May 14, 1963 '7 Sheets-Sheet 6 g. or

INVENTOR. do: NApCe-Z A auv' BY 4 LI, 414 1.; LQI W or J -LU L F May 14, 1963 J. M- WOLFF 3,089,214

MACHINE FOR MANUFACTURING AIR CAVITY BUILDING BLOCKS Filed Oct. 6, 1959 '7 Sheets-Sheet 7 I INVENTOR.

BY dim, @144; @r: Ame Z;

Patented May 14, 1963 3,089,214 MACHINE FGR MANUFACTURING AIR CAVITY BUILDING BLOCKS Joe Marcel Wolff, Elmhurst, N.Y., assignor, by mesne assignments, to Cav=Wal Block Corporation, New York,

N.Y., a corporation of New York Filed (let. 6, 1959, Ser. No. 844,652 8 Claims. (Cl. 254I) This invention relates to a machine for manufacturing air cavity building blocks.

The present invention is an improvement over the machine shown in United States application Serial No. 527,769, filed August 11, 1955, now Patent No. 2,987,- 795, by Julius Adams, for Machine for Manufacturing Building Blocks and assigned to the assignee of the present application.

Air cavity building block is a term used herein to denote a building block including at least two slabs with parallel co-extensive portions, the slabs being made of concrete, cinder or the like hardened cementitious material and being unconnected by any webs or partitions of the material of which they are fabricated whereby to prevent conduction of heat and/or moisture from one of the slabs when it is on the exterior of a building to the other slab which then is on the interior of the building. The slabs of an air cavity building block are permanently inter-connected by metal elements which, for convenience, will hereinafter be referred to as tierods, Thus, an air cavity block building wall in effect consists of an outer masonry wall and an inner masonry wall spaced by an air cavity and unconnected except by slender metal rods or the like.

It is the principal object of my invention to provide a machine of the character described which is simpler, and more regular, speedy and efiicient in operation than the machine which is shown in said co-pending application.

It is another object of my invention to provide in the machine of the character described a new and effective mechanism for injecting tierods into a mold box whereby this operation can be performed speedily, accurately, at a low cost, and in a foolproof manner.

It is another object of my invention to provide in a machine of the character described an improved mechanism for releasably holding the tierods in the mold box after injection, the mechanism being such that a positive grip is assured and yet a quicker release is obtained, the same being reliable in operation despite the presence of the all-pervading gritty particles and vibrations.

It is another object of my invention to provide a machine of the character described which constitutes relatively few and simple parts and is particularly easy to operate even by an unskilled worker whereby construction costs for air cavity blocks can be kept low, and, nevertheless, strong, economical and durable blocks can be fabricated.

Other objects of my invention will in part be obvious and in part will be pointed out hereinafter.

My invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts which will be exemplified in the construction hereinafter described, and of which the scope of application will be indicated in the appended claims.

In the accompanying drawings, in which is shown one of the various possible embodiments of my invention,

FIG. 1 is a perspective view of a new machine embodying my invention;

FIG. 2 is a partly fragmentary side view of the tierod injector station;

FIG. 3 is a sectional view taken substantially along the line 33 of FIG. 2;

FIG. 4 is a top view of the tierod injector station with the tierod magazine removed;

FIG. 5 is a sectional view taken substantially along the line 5-5 of FIG. 4;

FIG. 6 is an enlarged sectional view taken substantially along the line 6-6 of FIG. 2;

FIG. 7 is a sectional view taken substantially along the line 77 of FIG. 4, said view being extended to include the mold box and showing the positions of the parts at the start of a molding cycle;

FIG. 8 is a view similar to FIG. 7, but illustrating the mold box alone and showing the positions of the parts just after injection of a tierod;

FIG. 9 is a view similar to FIG. 8, but showing the positions of the parts after dumping of the concrete mix;

FIG. 10 is a view similar to FIG. 7, but showing the positions of the parts after tamping of the concrete mix;

FIG. 11 is a view similar to FIGS. 8 and 9, but showing the positions of the parts during discharge of an air cavity block from the mold box;

FIG. 12 is a sectional view taken substantially along the line 1212 of FIG. 8;

FIG. 13 is a sectional view taken substantially along the line 13-43 of FIG. 9;

FIG. 14 is a view similar to FIG. 13 but showing the positions of the parts after partial discharge of an air cavity block from the mold box;

FIG. 15 is an enlarged sectional view taken substantially along the line 1515 of FIG. 8 and illustrating the releasable tierod retainer;

FIG. 16 is a top view of the mold box;

FIG. 17 is a top view of the pallet;

FIG. 18 is an enlarged sectional View taken substantially along the line 1813 of FIG. 17 and showing the ribbed transverse contour of the pallet;

FIG. 19 is an enlarged fragmentary sectional view taken substantially along the line 19-19 of FIG. 17 and showing a longitudinal section of the pallet;

FIG. 20 is a top view of a tierod;

FIGS. 21, 22 and 23 are sectional views through the tierod, the same being taken substantially along the lines 212I, 2222, and 23-23, respectively, of FIG. 20;

FIG. 24 is a perspective view of a finished air cavity block;

FIG. 25 is a top view of said block;

FIG. 26 is a side view of a part of a wall composed of said blocks;

FIGS. 27 and 28 are enlarged sectional views taken substantially along the lines 27-27 and 2S-28, respectively, of FIG. 26;

FIG. 29 is a perspective view of a corner of a Wall composed of said blocks;

FIG. 30 is a bottom View of a corner block embodying the present invention; and

FIG. 31 is a fragmentary top view of said corner block.

Referring now in detail to the drawings, the reference numeral 40 denotes a complete machine for making air cavity blocks, said machine in part constituting standard commercial equipment and in part embodying improvements of my invention.

The standard commercial part of the machine is that portion which is not particularly adapted to produce air cavity blocks, that is to say the portion which could be used in the fabrication of ordinary building blocks consisting of a monolithic body of concrete having plural vertical cavities. Said portion of the machine constitutes a stand 42 which supports a feed hopper 44 in which plastic concrete is deposited, being received from a convenient source thereof as, for instance, a concrete mixer. The wet concrete is transferred to a feed drawer 46 which reciprocates from a rear position in which it receives concrete from the hopper 44 to a forward position in which it deposits a metered quantity of concrete in a mold box 48. The feed drawer includes a suitable mechanism for retaining the concrete in the same until the extreme forward position has been reached for discharge into the mold box. Said mold box is not furnished with the old type of commercial machine but is of special construction and in general embodies the concept disclosed in the aforesaid co-pending application. The mold box will be described in detail hereinafter.

The machine further conventionally includes a tamper which cannot be seen in FIG. 1 but which will later be described in conjunction with the mold box. Another conventional part of the machine is a pallet support 5%. As is usual in block molding machines of this type, the mold box is stationary and the tamper and pallet support are moved up and down, as by hydraulic pressur In an operating cycle of the machine a proper amount of plastic concrete is dumped from the feed drawer into the mold box while the tamper is in elevated position and while the pallet support is in uppermost position holding a pallet against the normally open bottom of the mold box. Thereafter, the feed drawer retracts and the tamper descends to compress the concrete in the mold box. Subsequently, the tamper-s and pallet support move down at the same rate of speed until the molded block is clear of the mold box. Thereafter, the tampers stop their vertical descent but the pallet support continues to move downward whereby to separate the finished block from the tamper. Then the finished blocks are brought forward on a conveyor 52.

The foregoing standard commercial portion of the machine 40 has been described in a general way in order better to understand the construction and operation of the various machine parts which hereinafter will be detailed. Since such portion of the machine is entirely conventional, for a more detailed description thereof, if the same should be desired, reference is made to the Instruction Manual of the Columbia Machine Works for the model 8 or 10 Columbia block machine manufactured and distributed by the Columbia Machine Works of Vancouver, Washington, U.S.A., the said Instruction Manual having been issued on September ll, 1956.

The portion of the machine which is not available as standard commercial items, except recently through the assignee of this application, essentially includes the mold box, the pallet and the tierod injector station which now will be described in detail.

The mold box 48 is, in general, of such shape as to define the outer vertical surfaces of the desired air cavity block which consists essentially of two parallel slabs. More particularly, the mold box 48 includes four vertical walls, to wit, a pair of outside vertical walls 54, 56 (FIG. 7) and a pair of inside vertical walls 58', 60, these latter two defining the sides of the core. All of the walls are parallel and coextensive in the particular mold box being described which is the mold box for a stretcher or sash block. All of the walls 54, 56, 58, 6t terminate at opposite end walls 62, 64 thereby defining two side-by-side spaced parallel cavities 66, 68 for the molding of the two parallel slabs of an air cavity block. It will be noted that both the top and bottom of each cavity is open. The upper edges of the core walls 58, 60 are connected by a horizontal cover 70. The ends of the cavities are formed to provide cooperating dove-tailed grooves and tongues on the block, this being conventional.

The mold box conventionally is held stationary by side supports 72 fixed to the box and locked with keys 73 to stationary flanges 74 on the stand 42.

For a reason which later will be apparent, the core walls 58, 60 are provided with one or more, in the illustrated example, two, pairs of vertical transversely registered slots '76 extending upwardly from the lower edges of said walls so as to provide communication between the cavities 66, 68 and the space between the core walls. Said pairs of slots 76 are located in positions at which the tierods are to be placed in the mold box.

The mold box also includes a pair of vertically extending pendent metal strips '78 at opposite sides thereof, the lower ends of which terminate in V-shaped cam tips for conventional registering cooperation with the pallet.

In accordance with a feature of my invention, a pallet 86 is included Which is of such configuration that it can be utilized for making air cavity blocks of various lengths, stretcher blocks, sash blocks and corner blocks. in other words, a large number of a single kind of pallet can be employed for making many varieties of air cavity blocks.

The construction of the pallet best can be seen in FlGS. l7, l8 and 19. In essence, the pallet constitutes a long wide generally flat oblong plate which is made from a relatively inexpensive yet durable material. An excellent substance for this purpose is a laminated thermosetting plastic, for instance, an asbestos fiber impregnated phenol formaldehyde condensation resin. The pallet is rectangular, being wider than the widest block and longer than the longest block to be made. Said pallet is formed with two elongated ribs 82, 84, i.e., ribs that run parallel to the length of the pallet. These ribs are designed to form grooves 85, i.e., recesses, in the undersides of the slabs constituting the air cavity block so that the blocks can be interlocked with beads on the top of underlying blocks. The ribs are so located that each runs down approximately the center of the slab which is to be formed thereover (see FIG. 11). To both sides of each rib the pallet is formed with channels 86, that define the bottom walls of the slabs and the side walls of the ribs 82, 84. Adjacent the outer edges of the two outermost channels, the pallet is fashioned with slight longitudinal beads 88 the purpose of which is to form a mortar-receiving slot 3? along the lower outer edge of each of the slabs that will constitute the air cavity block.

Further, the pallet includes ledges, i.e., elevated flats, 90 running along both sides of the length thereof. The height of these ledges is intermediate that of the tips of the ribs 82, 84 and the bottoms of the channels 36. Moreover, the height of the ledges is below that of the beads 88. Thereby the slots 89 are enabled to communicate with the outer side surfaces of the slabs composing an air cavity block so that the slots can be pointed after several courses of blocks have been laid and it is not necessary to lay mortar over one course of blocks before the next course is in place.

Still further, the pallet is provided with another ledge 92 which extends across one end only of said pallet at the same level as the ledges 90. The ledge 92, as later will be appreciated, is utilized to provide a mortar-receiving slot 93 at the outer lower end edge of either a sash block or corner block and to eliminate at this lower edge the unsightly notches which otherwise would be left by the ribs 82, 84-. The tampers are similarly shaped to form a mortar receiving shoulder 94 at the top outer end of each block adjacent each of the longitudinal ridges 95 that engage the grooves 85. The long edges of the platen are notched as at 96 to cooperate with the aligning cam strips 78.

When a pallet is assembled with the mold box 48 to form a stretcher block, the mold box occupies the position shown in dot-and-dash lines in FIG. 17. Inspection of this figure makes it clear that a pair of ends of the cavities in the mold box slightly overlie the end ledge 92 and the outer sides of the cavities slightly overlie the side ledges 90 thereby forming the mortar slots heretofore mentioned.

To admit the tie rods one side wall 56 of the mold box is provided with a pair of horizontally registered openings 97 which are longitudinally registered with the upper ends of the slots 76. These openings constitute the inner ends of stub tubes 98 which extend laterally and horizontall" away from the mold box to chamfered outer ends 1%. Said tubes constitute feed guides for tierods.

The machine has a tierod injector station 102 mounted alongside the mold box, the machine 40 illustrated in FIG. 1 being constructed to make two air cavity building blocks at a time so that it includes two tierod injection stations. Specifically, at each tierod injector station a large number of elongated metal tierods 104 are contained in two Wedgeshaped magazines 106 each of which includes one inner vertical wall 108 and one flaring outer wall 110. .The walls of each magazine are spaced apart adjacent their lower ends a distance slightly in excess of the diameter of a tierod so that the rods conveniently can be fed one by one from the bottoms of the magazines. The breadth of the magazines is just sufficient to accommodate the lengths of the tierods. Thus, the tierods are maintained in orderly position within the magazine, all of the rods being horizontal, parallel to one another and co-extensive, i.e., with their ends in registry.

As will be seen in FIG. 6, the narrow open bottom end of each magazine leads into a different vertical feed chute 112 that terminates a short distance above a transfer plate 114. The transfer plate is horizontal and is mounted to slide on an underlying pair of flat guides 116, each of which is slotted to provide channels 118 extending in a direction perpendicularly to the sides of the mold box and being respectively registered both horizontally and vertically with the two feed guides 98. The transfer plate likewise is provided with slots 120, the spacing between the slots 120 being identical to the spacing between the channels 118 and between the feed guides. Said transfer plate is guided for movement in a direction perpendicular to the longitudinal axes of its slots 120 by side gibs 122.

Movement of the transfer plate is effected by a fluid motor 124 including, for example, a hydraulic cylinder 126 in which a piston -(not shown) is located. Said piston is connected to a drive shaft 128 that is attached to the transfer plate 114. In one extreme position of the hydraulic piston the slots 120 in the transfer plate are aligned with the vertical chutes 112 of the tierod magazines, and in the other extreme position of the hydraulic piston said slots 120 are lined up with the channels 118. Accordingly, when the piston moves into the first of said positions, a pair of tierods will descend from the magazines, one falling into each of the slots 120. Thereafter when the transfer plate shifts to its other position the tierods carried in the slots 120 will fall into the channels 118. As the transfer slots move away from the magazines, the lowermost tierods in the magazines will descend until they strike the top surface of the transfer plate so that the slots will be ready, upon the return movement of the transfer plate, to accept a fresh pair of tierods. It will be apparent that the spacing between the bottoms of the vertical chutes and the transfer plate is less than the diameter of tierods handled in the magazines and preferably less than one-half of such diameter so that there will be no tendency for the tierods to jam at the lower terminals of the chutes.

Desirably, the lower ends of the flaring walls 110 of the magazines and the outer walls of the chutes are skeletonized, as indicated, by the provision of broad vertical slots 13!) (see FIG. 2) so that if during operation of the machine the tierods should inadvertently become jammed they easily can be shifted back into proper orientation.

The tierods are quite heavy, particularly when considered en masse, so that it is particularly undesirable for them to become wedged in the magazines. To prevent this, an arrangement is included to relieve a major portion of the weight of the mass of rods on the few rods located near the bottoms of the magazines and in the chutes, this relief being provided at least once during each cycle of operation of the machine.

For the foregoing purpose the tierod injector station includes at each magazine a pair of lifting and agitating cams 132 mounted to oscillate with a horizontal shaft 134. The arcuate free tips of the cams extend into the magazine through the slot 130 and are spaced from the inner vertical wall 108 a distance slightly in excess of the 6 diameter of a tie rod. Each cam includes an upper side edge 136 which is substantially horizontal, said edges being coplanar and carrying a major portion of the weight of the tierods in the magazine.

It will be appreciated that when the cams are rocked they will raise the tierods above them, thereby removing most of the weight imposed on the tierods in the chute and permitting them to feed freely. Moreover, operation of the cams agitates the tierods so as to break up any incipient jams and loosen the flow of clogged tierods.

The shafts 134 for the cams are journalled in brackets 138 that extend outwardly from pedestals 140 on which the magazines 106 are carried. Bo-th shafts 134 have secured thereto pendent rocker arms 142 the lower ends of which are pivotally connected to opposite ends of a horizontal drive link 144. Mounted on the drive link near the center thereof are a pair of spaced collars 146 that lie on opposite sides of a drive block 148 fast on the transfer plate 114. Thus when the transfer plate approaches one of its extreme positions, one of the collars will strike the block and cause one of the cams 132 to be rocked upwardly and the other downwardly while, when the transfer plate approaches its other extreme position, the cams will experience an opposite oscillation. The flat guides 16 are firmly secured on a :base plate 150 which carries the fluid motor 124. In turn the base plate is fixed to an underlying frame plate 152 that is fastened to a stationary skeleton support 154 suitably attached to the stand 42. Extending away from the edges of the guides 1 1-6 facing the mold box are tubes 156 (see FIG. 7) in axial alignment with the stub tubes 98. The free ends of tubes 98 and 156 are close to but spaced from one another so that components of the machine, which, as soon will be pointed out, traverse these tubes and at certain stages of their operation may pick up Wet cement, will have the cement stripped or shaken off as they cross the gaps between the tubes. Moreover transmission of vibration from the mold box to the injector station is minimized.

The tierod injector station includes suitable means for driving tierods from said station into the mold box intermittently, in proper timed relationship to the movements of the other parts of the machine. Said means includes a pair of feed shafts 158, each registered axially with a different one of the slots 118. The feed shafts are at the ends of the flat guides 116 opposite from the lead out tubes 156. Each feed shaft is attached at one end to a piston '(not shown) of a fluid motor 160 including, for example, a hydraulic cylinder 162. The hydraulic cylinders are secured by brackets 164 to a truck 166 constituting a pair of crossbars 168 carried on a pair of longitudinal frame members 170. The ends of the cross bar overhang the frame members and serve as shoes which ride on the frame 154 which acts as tracks so as to be movable in a direction parallel to the longitudinal axes of the channels 118.

For a reason which will be described later herein, means is included axially to shift the truck 166, said means preferably comprising a fluid motor 174 constituting, for example, a hydraulic cylinder v176 securely attached to the frame plate 152. The piston (not shown) contained within said cylinder actuates a rod 178 that is attached to the forward crossbar 168,

In the operation of the tierod injector station, initially the feed shafts 158 are withdrawn by their hydraulic motors 160 to positions (see FIG. 7) in which their tips are located in the slots 118 just behind the remote ends of the tierods in said slots. Next the fluid motors 160 are actuated. Their throws are substantial and sufficient to drive the tierods located in front of them all the way through the tubes 156 and 98 and through the openings 97 all the way into the mold box, as shown in FIG. 8. In this position the tierods are centered with respect to the mold box core so that each end of each tierod is located in a different one of the mold cavities 66, 68 and 7 is similarly spaced from the outer walls 54, 56 of the mold box. The lengths of the tierods are less than the distance between said outer walls 54, 56, conveniently approximately two inches shorter, so that in the aforesaid positions of the tierods the ends of the tierods are spaced inwardly about one inch from the walls 54, 56.

Now, while the fluid motors 160 remain actuated, and the feed shafts 158 accordingly fully extended, the fluid motor 174 is actuated to shift the truck 166 away from the mold box. The movement effected by the fluid motor 174 is considerably less than that brought about by the fluid motors 160 and is just enough to retract the tips of the feed shafts 158 back to a position, as shown in FIG. 9, Where they are approximately flush with the inner surfaces of the mold box outer wall 56.

The .core of the mold box is provided with a suitable mechanism for retaining the tierods in position after they have been injected into the mold box and yet for permitting the tierods to be withdrawn from the mold box through the slots 76 after the molding of an air cavity block has been completed. In accordance with the invention, said retaining mechanism is of particularly simple construction so that its operation will be highly reliable and is actuated by a fluid motor whereby proper operation of the aforesaid mechanism is insured despite the adverse operating conditions created by the ubiquitous abrasive particles and vibrations.

More particularly the tierod retaining mechanism constitutes a saddle 180 (see FIG. 12) of inverted U- shape contained slidably between the inner mold box walls 58, 60. The upper reach 182 of the saddle is located directly beneath the horizontal cover 70 of the core and slides on a pair of horizontal transverse rollers 13 irotata'b-le on cross-shafts 186 that are carried at their opposite ends on the core Walls '58, 60. Both ends of the reach 132 have rigidly suspended therefrom dependent legs 188 from one edge 100 of each of which a step 192 projects. The steps'192 are spaced apart a distance equal to the center-to-center spacing between the slots 76' in the walls 58, 60', so that it is possible so to manipulate the saddle as to either expose or cover said slots.

The saddle is actuated by a fluid motor 194-, e.g., a hydraulic motor, having a cylinder 196 fastened to an end wall of the mold box. The piston (not shown) in the hydraulic cylinder actuates a drive rod 198 secured to the saddle 180. The drive rod has two extreme positions in which it is located by the hydraulic motor. One of these positions is shown in FIG. 12 and the other in FIGURE 13. In the position shown in FIG. 12 the drive rod 198 is extended a distance such that the steps 102 of the saddle cover all except the upper ends of the slots 76. This is the position of the saddle at the time that tie rods are injected into the mold box. In the other position of the drive rod 198 .shown in FIG. 13, the saddle has been shifted toward the hydraulic motor 194 a distance sufficient to expose the full and uninterrupted length of the slots 7 6.

It will be observed that both legs 188 of the saddle carry on the edges 190 a short distance above the steps 192 cantilever spring clips 200. The free operative end of each of these clips essentially is a leaf spring that is deformed, i.e., shaped, to provide a central vertically extending groove 202 (see FIG. 15) and side wings 204, the latter sloping toward the supporting legs 18!. The clips are located in the horizontal plane of the channels 118 and project forwardly from the legs 18S toward the path of movement of tierods being injected into the mold box, in a position such that they will be brushed by tierods being fed through slots 76-. Each clip presents a convex surface to a tierod, i.e., it is arched or bowed toward the tierod, and the tierod engages the clip above the high point of the arch so that when the clip is depressed somewhat towards the supporting leg 183 there will be a net force having an upward component exerted on the tierod in the slot 7 6 thereby preventing the tierod from dropping. in addition, the tierod is supported in place by the step 192.

The clips 200 have a further function, for the understanding of which the contour of the tierod must be explained.

Referring to FIGS. 20-23, a tierod such as is employed in the present invention constitutes an elongated bar of a strong metal such, for instance, as malleable iron. A though insofar as the present invention is concerned, the tiered injector station will, within the scope of the present invention, handle tierods of any elongated configuration, it is preferred to employ a tierod which will be anchored with great security in the concrete slabs of the air cavity block. A conventional tierod, such as ordinarily has been employed heretofore in the hand or semi-automatic molding of air cavity blocks, usually consisted of a length of conventional concrete reinforcing rod which was a steel or iron rod having a rough surface, i.e., a surface which may be best described as one having a hammered appearance. Such tierods upon occasion additionally included a few spaced protuberances, these usually extending in a direction axially of the rod.

Pursuant to an ancillary feature of my invention, the tierods are of cruciform cross-section, that is to say, they are formed with high elongated fins, i.e., ribs 206. Although the number of ribs may vary, the desired shape is, as has just been stated, cruciform, that is to say, fourribbed, inasmuch as the utilization of a .greater number of ribs or ribs differently angularly related appreciably weakens the strength of the concrete lying between the ribs, and the utilization of a lesser number of ribs too greatly reduces in one direction or another the metalto-concrete interface that resists relative movement of the slabs and tierods.

In addition to its cruciform section, each tierod includes several annular ribs, to wit, a central annular n'b 208 and three axially spaced annular ribs 210, 212, 214 to either side of the central ribs. The central rib 208 is of circular cross-section as are the two innermost annular ribs 210. However, the annular ribs 212, 214 are of mutilated rectanguloid shape, having circular ends and fiat parallel sides (see FIGS. 21 and 22). Said flat sides, like the cruciform shape, increase the resistance to relative turning movement of the bond between the tierods and slabs. In order that maximum resistance be obtained to turning in either direction about the longitudinal axis of the tierod, the flats on the annular ribs 212, 214 are oriented oppositely to one another.

It might seem that the special shaping of the tierods so as to increase their resistance to relative turning movement between the tierods and slabs is unnecessary inasmuch as there are two spaced tierods connecting the slabs, and since when the blocks are used the concrete has hardened around the imbedded ends of the tierods. There are, however, certain practical problems which the use of the specially constructed tierod overcomes.

For example, when a block is freshly molded, the concrete is only a few seconds removed from its wet plastic condition, having been, as will be pointed out hereinafter, compressed and vibrated by suitable mechanisms. Although at this time the concrete block is fully capable of retaining its own shape, it is very frail. It has been found that small shocks, such as are incident to normal handling, often will loosen a convention-a1 reinforcing tierod. Wlhere, however, the unique form hereinabove described is employed, the tierods do not loosen with any handling less severe than that which would break the slabs themselves.

Moreover, under certain conditions only a single tierod connects the pair of slabs of an air cavity block. For instance, on occasion a stretcher block will be too long for the space to be filled and it becomes necessary to shorten the block. if the shortening is appreciable, one tierod will be removed, thus leaving only a single tierod to hold the two slabs together. At such times the torsional stress placed on the bond between the tierod and slabs becomes appreciable, and the unique construction of the present invention is highly effective in preventing relative movement.

In addition, corner blocks of the air cavity type, which consist of one right-angled slab and one short slab, although molded with the two slabs in one piece, have these slabs disconnected from one another prior to use in erecting a masonry wall, and at this time are connected only by a single tierod.

It has been found that under all circumstances where but one tierod connects the two slabs of an air cavity block, no rotation .between the two slabs will take place where they are connected by a tierod constructed in accordance with the present invention.

Attention also is directed to the central annular rib 208. One of the functions thereof is to act as a drip shield preventing conveyance along the tierod of any condensate that may be formed in the moist interior of an air cavity wall.

When tierods are fed into the mold box, they move at a high speed. This is opposed by the friction developed upon engagement with the clips 20 so that the instant forward motion of the feed shafts 158 ceases, the tierods come to a dead stop. Moreover the stroke of the feed shafts 158 is so regulated, that at the end of their feed-in motion the central annular ribs 208 are aligned with the grooves 202 in the clips. In this fashion exact location of the tierods within a molded air cavity block is ensured.

The two ends of a tierod 194 are frustoconically shaped, tapering outwardly. This arrangement enables a tierod to cam its way past obstacles such, for instance, as the clip 200, without having its forward movement checked until the time desired. Thus shaping the forward end of the tierod also makes certain that it will have no difliculty in entering the exposed end of a guide tube 98. The inward movement of the tierod is further facilitated by the chamfer 100 on said guide tube and -by the outflaring configuration of the wings 204 on the clips.

The operation of the machine can be most easily followed if it be assumed that all parts are in their initial positions. At this time the feed drawer 46 is retracted for receipt of plastic concrete from the hopper 44. The tampers 216 are at a level higher than the feed drawer. The pallet support 50 is in its uppermost position pressing a pallet 80 against the bottom of the mold box 48. Said pallet is so positioned with respect to the mold box that each of the ribs 82, 84 extends longitudinally of a different mold cavity 66, 68 and runs approximately centrally thereof. The beads 88 are located near the long bottom edges of the cavities 66, 68 adjacent the outer sides thereof. The tops of the cavities are fully open. The tierod feed shafts 158 are fully retracted to their FIG. 7 position, and the truck 166 is in that one of its two extreme positions in which it is closer to the tierod magazines 106. The transfer'plate is arranged with the slots 120 thereof directly beneath the feed chutes 112 and out of alignment with the channels 118. The saddle 180 is in that one of its two positions shown in FIG. 12 in which the steps 192 block off all but the upper ends of the slots 7 6.

The machine is hydraulically operated and any conventional timing mechanism is utilized to insure properly integrated operation of the various mechanisms.

At the start of a cycle, the first operation is energization of the hydraulic motor 124 to shift the transfer plate, so that the slots therein will laterally move one pair of tierods from beneath the feed chutes to over the channels 118. These two single tierods drop into the channels ahead of the front ends of the feed shafts 158, as shown in FIG. 7.

Next, the hydraulic motors 160 are actuated. This will cause the feed shafts to push the two tierods located in the channels 118 forwardly, first through the tubes 156, then across the gaps at the ends of said tubes, then through the tubes 98, then across the cavity 68, then through the core and across the steps 192, and finally into the cavity 66. Forward movement of the feed shafts 158 stops when the tierods are symmetrically located in the mold box, as shown in FIG. 8. As mentioned earlier, although the tierods are propelled into the mold box at great speed, they nevertheless come to an abrupt halt when the feed shafts stop their motion because said tie-rods are decelerated by the spring clips 200, and, moreover, are maintained centered by cooperation between the middle annular ribs 298 on the tierods, and the grooves 202 on the clips.

At this time or at any subsequent time prior to the completion of the cycle, the hydraulic motor 124 is driven in the opposite direction to realign theslots 120 in the transfer plate with the tierod feed chutes.

Now, the hydraulic motor 174 is actuated to extend its rod 178 and shift the truck 166 away from the tierod magazines a distance sufficient to locate the tip-s of the shafts 158 flush with the inner surface of the side wall 56 of the mold box (see FIG. 9).

Immediately after the tierods have been disengaged by the feed shafts but supported within the core, or slightly prior thereto, the feed drawer, which now contains plastic concrete, moves forward over the mold box and beneath the tampers 21-6 and deposits a metered quantity of concrete in the two cavities 66, 68. The feed drawer thereupon retracts. The parts now occupy the position shown in FIG. 9.

Next the tampers 216 descend to engage the upper surfaces of the concrete in the cavities while at the same time, the mold box is severely vibrated, as is conventional in the art. Optionally, vibration may be started at an earlier stage, as for example, during deposit of the concrete into the cavities. The undersurfaces of the tampers are shaped to form the raised interlocking ridge running longitudinally and centrally of the upper surface of each of the slabs and also to form the mortar receiving slots 89.

At approximately the moment that the tampers engage the tops of the slabs, the hydraulic motor 194 is actuated to pull the saddle from its position shown in FIG. 12 to its position shown in FIG. 13. This allows the tierods to drop slightly in the slots 76 as can be observed by comparison of FIGS. 12 and 13, and of FIGS. 9 and 10. Such descent of the tierods is of particular advantage inasmuch as it prevents the formation of air pockets beneath the tierods which would be caused if the tierods were held stationary while the tampers were descending. It has been found that even the severe vibration to which the mold box is subjected at this stage of the operation, does not sufiice to fill the spaces which otherwise would be formed beneath the tierods.

During the foregoing stages of the molding operations, the pallet support remained in its elevated position. However, now that the molding is completed, the pallet support starts to lower and the tampers move downwardly at the same speed, the vibration having been stopped, until the slabs clear the mold as shown in FIG 11. It will be noted that While the block descends, the tierods move downwardly through the slots 76. It also may be pointed out that the comparatively narrow width of said slots has been found not to permit much extrusion of concrete therethrough, and, furthermore, it will be appreciated that the somewhat roughened surfaces resulting due to the presence of said slots will not be seen in a finished mortar wall, inasmuch as the surfaces on which they appear are entirely located within the air cavity.

After the slabs have cleared the mold box, the pallet support continues its downward travel but the tampers stop so as to free the upper surfaces of the now finished air cavity block. Thereupon, conventional mechanisms engage the block and guide it forwardly onto the con veyor 52.

The configuration of a finished air cavity stretcher block 218 is shown in FIGS. 24-28. Said block includes two slabs 220, connected by a pair of tierods 104, each located about one-fifth of the way in from the ends of the slabs, although it will, of course, be understood that this spacing is not critical. The upper and lower outer edges of the slabs have the mortar receiving slots 89, the slots in any given block being in the same vertical plane as the slots of the blocks above and below it so as to form channels for the reception of mortar 222 (see FIG. 27). This mortar desirably is applied after several courses of blocks have been laid, that is to say, it need not be applied to the upper surface of a given course of blocks prior to laying another course on top of the same, whereby the blocks lend themselves to speedy erection by the laying up of several courses, and only then pointing the joints with mortar. The ridges 95 on the tops of each of the slabs are received in the grooves 85 of the matching slabs to interlock the blocks and restrain them against relative lateral movement, it being this keying action that allows several courses to be laid before pointing.

It also is desirable to form the blocks with vertical :mortar receiving slots 224 (see FIG. 28) by suitably forming the cavities (see FIG. 16), so that mortar 226 can be interposed at the vertical parting lines between blocks in the same course.

The reference numeral 228 denotes a corner block '(see FIGS. 30 and 31) which can be molded with the same pallet 80 as that employed to mold the stretcher block 218. The mold box employed to make the corner block is not shown. However, its shape will be readily understood from the shape of the corner block, it being noted that the web 230 shown in dotted lines in FIG. 30 is part of the block as molded and only is shown in dotted lines to indicate that it is designed to be weak, so that it can be broken away from the block by a mason before installing it as part of a wall. Said web 230 conventionally is weakened by forming depressed lines to define it and by making it to lesser height than the slabs. Thus, although a corner block as initially molded has one right angle slab and a second slab which is integral with the right angle slab, in a complete wall it constitutes two separate slabs.

Attention is called to the fact that the grooves 85 at the bottom of a corner block terminate short of the outer end of said block due to the cooperation between the ledge 92 and the adjacent end of the corner mold box. This termination of the grooves provides a clean end face to the corner block, so that in a corner of a building, as shown in FIG. 29, there will be no ugly notches which otherwise would be present due to the grooves 85. Moreover, since the ledge 92 is higher than the channels 86 (see FIG. 19), the outer end edge of the corner block of which the grooves 85 terminate short, is provided with the mortar receiving slot 93.

To enable the corner blocks to be crossed, the tampers used in making the same do not form the upper rib over the full length of the body. Rather, such rib 232 extends slightly less than half the body, as shown in FIG. 31.

Optionally, in the molding of stretcher blocks the mold box is located off the ledge 92 to enable the grooves 85 to extend fully from end to end of each slab.

It thus will be seen that I have provided a machine .for manufacturing air cavity building blocks which achieves the various objects of my invention and is well adapted to meet the conditions of practical use.

As various possible embodiments might be made of my above invention and as various changes might be made in the embodiment above set forth, it is to be understood that all matter herein described or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, 1 claim as new and desire to secure by Letters Patent:

1. In a machine for fabricating an air cavity block constituting at least two slabs with parallel coextensive portions unconnected except by at least one tierod, and

which machine includes a mold box having inner and outer side walls and end walls defining separate elongated parallel cavities for the slabs, the inner side walls of the mold box at each cavity having registered slots extending inwardly to closed bottoms from like edges of the mold box: that improvement comprising, a source of tie rods, means providing an opening in an outer side wall of only one of the cavities in registry with the closed bottoms of said slots, and means for feeding tierods into the mold box from the outer side thereof through said opening, perpendicular to said side walls and through said slots adjacent the closed bottoms thereof.

2. A machine as set forth in claim 1 wherein the tierod feeding means feeds tierods axially of their lengths into the mold box.

3. A machine as set forth in claim 1 wherein the tierod feeding means includes a member having a feeding tip and means to reciprocate said member from a position in which the tip is remote from the opening in the side wall to a position in which the tip protrudes through said opening into a cavity and then to a position within said opening and out of the cavity so that the tip will lie substantially flush with the outer wall of the mold box during a molding operation.

4. A machine as set forth in claim 1 which further includes a tierod magazine wherein the feeding means is disaligned with the magazine and wherein a transfer plate is provided for shifting a tierod at a time from the magazine to the feeding means.

5. A machine as set forth in claim 1 wherein the tierod feeding means includes a guide tube extending toward the mold box, wherein the mold box includes another guide tube extending toward and in registration with the firstnamed guide tube and wherein the tierod feeding means further includes a feed shaft extendable through said tubes, said tubes being separated from one another by a clear space to permit concreti'ous material to drop therethrough when the feed shaft retracts.

6. A machine as set forth in claim 1 wherein the tierod feeding means includes a feed element which pushes a tierod axially ahead of it into the mold box, the tip of said element entering into the mold box, said feeding means further including means to retract the tip of said element partially after pushing a tierod into the mold box so that the tip will lie substantially flush with the outer wall of the mold box during a molding operation.

7. A machine as set forth in claim 1 which further includes spring means within the mold box stationarily positioned between the side walls and in approximately registry with the closed bottoms of the slots so as to brush against the side of a tierod fed into said box and thereby check movement of the tierod when the tierod feeding means halts.

8. A machine as set forth in claim 7 wherein each said tierod has a medial annular rib and wherein the spring means includes a groove for engaging said rib so as to locate the tie rod in a predetermined position in the mold box.

References Cited in the file of this patent UNITED STATES PATENTS 799,709 Bradley et 'al. Sept. 19, 1905 899,091 Ballinger May 26, 1908 920,017 Bruner Apr. 27, 1909 940,935 Larsen Nov. 23, 1909 986,057 Wallin Mar. 14, 1911 1,119,095 Meece Dec. 1, 1914 1,188,415 Cordes June 27, 1916 1,425,015 Hyten Aug. 8, 1922 1,468,065 Williams Sept. 18, 1923 1,474,813 Browne et al Nov. 20, 1923 1,486,056 Straub Mar. 4, 1924 1,551,863 Berry Sept. 1, 1925 (thither references on following page) 13 14 UNITED STATES PATENTS 2,773,294 Pilling Dec. 11, 1956 2 37 7 1 Fab Ma 22 1945 2, 7, 3 Damien P 1957 2 492 415 c ge 27 1949 2,916,793 Elli-S et 1959 2,533,479 Leggot Dec. 12, 1950 2,583,104 Jentsch Jan. 22, 19-52 5 FOREIGN PATENTS 2,583,597 -Ryner Jan. 29, 1952 594,432 Great Britain Nov. 11, 1947 2,614,308 Burkhamd et a1. Oct. 21, 1952 902,234 Germany Jan. 21, 1950 

1. IN A MACHINE FOR FABRICATING AN AIR CAVITY BLOCK CONSTITUTING AT LEAST TWO SLABS PARALLEL COEXTENSIVE PORTIONS UNCONNECTED EXCEPT BY AT LEAST ONE TIEROD, AND WHICH MACHINE INCLUDES A MOLD BOX HAVING INNER AND OUTER SIDE WALLS AND END WALLS DEFINING SEPARATE ELONGATED PARALLEL CAVITIES FOR THE SLABS, THE INNER SIDE WALLS OF THE MOLD BOX AT EACH CAVITY HAVING REGISTERED SLOTS EXTENDING INWARDLY TO CLOSED BOTTOMS FROM LIKE EDGES OF THE 